btrfs-progs: cleanup and comment parse_range

Simplify a check and unindent some code.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2015-10-12 00:16:18 +02:00
parent 89c0e3b706
commit 9288d0bc23
1 changed files with 38 additions and 27 deletions

View File

@ -88,42 +88,53 @@ static int parse_u64(const char *str, u64 *result)
return 0;
}
/*
* Parse range that's missing some part that can be implicit:
* a..b - exact range, a can be equal to b
* a.. - implicitly unbounded maximum (end == (u64)-1)
* ..b - implicitly starting at 0
* a - invalid; unclear semantics, use parse_u64 instead
*
* Returned values are u64, value validation and interpretation should be done
* by the caller.
*/
static int parse_range(const char *range, u64 *start, u64 *end)
{
char *dots;
const char *rest;
int skipped = 0;
dots = strstr(range, "..");
if (dots) {
const char *rest = dots + 2;
int skipped = 0;
if (!dots)
return 1;
*dots = 0;
rest = dots + 2;
*dots = 0;
if (!*rest) {
*end = (u64)-1;
skipped++;
} else {
if (parse_u64(rest, end))
return 1;
}
if (dots == range) {
*start = 0;
skipped++;
} else {
if (parse_u64(range, start))
return 1;
}
if (*start >= *end) {
fprintf(stderr, "Range %llu..%llu doesn't make "
"sense\n", (unsigned long long)*start,
(unsigned long long)*end);
if (!*rest) {
*end = (u64)-1;
skipped++;
} else {
if (parse_u64(rest, end))
return 1;
}
if (skipped <= 1)
return 0;
}
if (dots == range) {
*start = 0;
skipped++;
} else {
if (parse_u64(range, start))
return 1;
}
if (*start >= *end) {
fprintf(stderr, "Range %llu..%llu doesn't make "
"sense\n", (unsigned long long)*start,
(unsigned long long)*end);
return 1;
}
if (skipped <= 1)
return 0;
return 1;
}